As methods of producing fatty acid alkyl esters by ester exchange between triglyceride-based fats/oils and lower alcohols, various methods are known. In such a reaction, for example JP-A 56-65097 shows that, while glycerin formed by a multi-stage reaction is separated, the reaction is promoted with use of an alkali catalyst.
To solve this problem, WO-A 2005/021697 has reported a process for producing fatty acid alkyl esters by using a solid acid catalyst.